To my understanding, Ki was talked about in a much different way, if at all, in the Koryu Bujutsu or Kobudo of Japan.

I'm currently reading a book called "Classical Fighting Arts of Japan: A Complete Guide to Koryu Jujutsu" by Serge Mol.

In it, Mol describes the historical origins of various terms such as Aiki, Ki, Wa, Yawara, Yawaragi, Yawaraka, etc.

According to Mol, it seems that Ki, Wa, and Aiki had very different connotations and meanings in the Koryu.

Plus, the focus of those arts are/were much different than the Gendai Budo, such as Aikido. The utilization of essoteric "forces" such as "Ki Power" were....well....somewhat ridiculous in the context of the old bugei. People were training so they wouldn't die in military combat. They studied more than just for self-defense and for personal self-discovery/perfection.